The present invention relates generally to agricultural machinery and more particularly to a baler with a flexible device for guiding bailing materials.
The invention is advantageously embodied in a round baler. A typical round baler is described in German Patent No. 43 08 646 and has a main frame, chassis, pick-up and feeding device for harvested crop, drive apparatus, and a hinged pressing chamber which is defined on both sides by fixed walls and circumferentially at least partially by endless belts and/or rollers. The belts are entrained over radial bearing idlers. A device for guiding binding materials, consisting of flexible material, partially encloses at least one of the idlers. In operation, feeding of the harvested crop is interrupted after the pressed round bale is completed. At that time the pressed round bale, while continuously rotating, is wrapped by either twine, net, film or other suitable material which precludes a ripping apart of the bale after ejection from the round baler. The binding material passes at least be partially around a press- or idler pulley, before it is caught between the rotating crop bale and the belts. For the binding material to pass around a press- or idler pulley it has proven worthwhile to use a guiding device which allows the binding material to advance into the press- or idler pulley and to be pressed over a portion of the press- or idler pulley so that it is caught and pulled in by the press- or idler pulley. Usually such a guiding device consists of a steel sheet; however, a steel plate has the disadvantage that it cannot react flexibly enough to an out-of-balance press- or idler pulley, or to accumulation of the binding material. In this context the term "flexible" means that it can adapt itself passively to a given form, that it essentially reacts inelastically, and that it does not expand considerably in one particular direction. The steel sheet as a guiding device is neither flexible nor elastic. Even when sectional bars are installed in a spiral method on the surface of an idler pulley in order to clean the inside of the belts, or when circumferential profiling is provided on the respective surfaces for improved feeding by the press roll, a steel sheet guiding device and respective roll do not cooperate optimally to pull in the binding material. In these situations, a long distance must be provided between a guiding device made of sheet steel and the press roll or the belt than is desirable for a reliable pull-in operation.
In German Patent No. 43 08 646, the use of flexible material in the manufacture of the guiding means is generally proposed. However, tests have shown that said flexible material is not rugged enough to withstand the wear for long periods of time, especially in the loop area of the idler pulley or, more particularly, the press roll. These tests also have shown that the skid reducing effect of the elastic material surface can interfere with a reliable pull-in operation of the binding material.
An object of the present invention is to provide an improved guide for bailing materials which overcomes the disadvantages discussed above.
Another object is to arrange a guiding means for binding materials in a way that it is elastic on the one hand, while on the other hand shows a high degree of stability.